The 1951 Formula One season was the fifth season of FIA Formula One motor racing. It featured the second World Championship of Drivers, which was contested over eight races between 27 May and 28 October 1951. The season also included several non-championship races for Formula One cars.

Juan Manuel Fangio won his first Drivers' Championship, beating reigning champion and Alfa Romeo teammate Nino Farina, as well as several drivers from their main rival, Ferrari. Alfa Romeo has not won any Formula One championship since.

Multiple teams, including Alfa Romeo, were running chassis from before World War II. Regulation changes for , however, would make them obsolete.

Teams and drivers The following teams and drivers competed in the 1951 FIA World Championship of Drivers. The list does not include those that only contested the Indianapolis 500.

Entrant Constructor Chassis Engine Tyre Driver Rounds Ecurie Belge Talbot-Lago T26C Talbot 23CV 4.5 L6 Johnny Claes 1, 3–8 Philippe Étancelin Talbot-Lago T26C Talbot 23CV 4.5 L6 Philippe Étancelin 1, 3–6, 8 Yves Giraud-Cabantous Talbot-Lago T26C Talbot 23CV 4.5 L6 Yves Giraud-Cabantous 1, 3–4, 6–8 Guy Mairesse 1, 4 Ecurie Rosier Talbot-Lago T26C Talbot 23CV 4.5 L6 Louis Rosier 1, 3–8 Henri Louveau 1 Louis Chiron 3–8 HW Motors HWM-Alta 51 Alta F2 2.0 L4 George Abecassis 1 Stirling Moss 1 Scuderia Ferrari Ferrari 375 Ferrari 375 4.5 V12 Luigi Villoresi 1, 3–8 Alberto Ascari 1, 3–8 Piero Taruffi 1, 3-4, 6–8 José Froilán González 4–8 Alfa Romeo SpA Alfa Romeo 159 Alfa Romeo 158 1.5 L8 s Giuseppe Farina 1, 3–8 Juan Manuel Fangio 1, 3–8 Toulo de Graffenried 1, 7–8 Consalvo Sanesi 1, 3–5 Luigi Fagioli 4 Felice Bonetto 5–8 Paul Pietsch 6 Enrico Platé Maserati 4CLT/48 Maserati 4CLT 1.5 L4 s Louis Chiron 1 Harry Schell 1, 4 José Froilán González 3 Toulo de Graffenried 4, 6 Paul Pietsch 6 Ecurie Espadon Ferrari 212 Ferrari 212 2.5 V12 Rudi Fischer 1, 6–7 Veritas Meteor Veritas 2.0 L6 Peter Hirt 1 José Froilán González Talbot-Lago T26C Talbot 23CV 4.5 L6 José Froilán González 1 Francis Rochat Simca-Gordini T11 Gordini 16C 1.5 L4 s Francis Rochat 1 Peter Whitehead Ferrari 125 Ferrari 125 1.5 V12 s Peter Whitehead 1, 7 Ecurie Belgique Talbot-Lago T26C Talbot 23CV 4.5 L6 André Pilette 3 Jacques Swaters 6–7 Pierre Levegh Talbot-Lago T26C Talbot 23CV 4.5 L6 Pierre Levegh 3, 6–7 GA Vandervell Ferrari 375 tw Ferrari 375 4.5 V12 Reg Parnell 3-4 Peter Whitehead 5 Graham Whitehead Ferrari 125 Ferrari 125 1.5 V12 s 4 Equipe Gordini Simca-Gordini T15T11 Gordini 15C 1.5 L4 s Robert Manzon 1, 4–8 Maurice Trintignant 1, 4–8 André Simon 1, 4–8 Aldo Gordini 4 Jean Behra 7 Eugène Chaboud Talbot-Lago T26C Talbot 23CV 4.5 L6 Eugène Chaboud 4 Scuderia Milano Maserati-Speluzzi 4CLT/50 Speluzzi 1.5 L4 Onofre Marimón 4 Paco Godia 8 Juan Jover 8 Joe Kelly Alta GP Alta 1.5 L4 s Joe Kelly 5 BRM Ltd BRM P15 BRM P15 1.5 V16 s Reg Parnell 5, 7 Peter Walker 5 Ken Richardson 7 Hans Stuck 7 Bob Gerard ERA B ERA 1.5 L6 s Bob Gerard 5 Brian Shawe-Taylor ERA B ERA 1.5 L6 s Brian Shawe-Taylor 5 Scuderia Ambrosiana Maserati 4CLT/48 Maserati 4CLT 1.5 L4 s David Murray 5–6 John James Maserati 4CLT/48 Maserati 4CLT 1.5 L4 s John James 5 Philip Fotheringham-Parker Maserati 4CL Maserati 4CLT 1.5 L4 s Philip Fotheringham-Parker 5 Duncan Hamilton Talbot-Lago T26C Talbot 23CV 4.5 L6 Duncan Hamilton 5–6 Antonio Branca Maserati 4CLT/48 Maserati 4CLT 1.5 L4 s Toni Branca 1, 6 OSCA Automobili OSCA 4500G OSCA 4500 4.5 V12 Franco Rol 7 Francisco Landi Ferrari 375 Ferrari 375 4.5 V12 Chico Landi 7 Birabongse Bhanudej Maserati-OSCA 4CLT/48 OSCA 4500 4.5 V12 Birabongse Bhanudej 1, 3-4, 8 Georges Grignard Talbot-Lago T26C Talbot 23CV 4.5 L6 Georges Grignard 8

– Did not attend on Swiss Grand Prix – Did not attend on Belgian Grand Prix – Did not attend on French Grand Prix – Did not attend on British Grand Prix

Team and driver changes

Alfa Romeo replaced their full-time driver Luigi Fagioli with Consalvo Sanesi, who had joined the team at the end of . Toulo de Graffenried also drove three races for the team, his only Grands Prix for a works team. Ferrari hired Piero Taruffi, who had made his F1 debut with Alfa Romeo at the end of last season, and José Froilán González, coming from a private Maserati team. Gordini waited until the fourth race in the calendar to compete. They added André Simon to their line-up. Talbot-Lago did not enter their works team for 1951. Three of their drivers decided to each take over a Talbot chassis and race it under their own name. Maserati, likewise, did not enter their works team. Driver Louis Chiron moved to Louis Rosier's private Talbot team, while Franco Rol would return later in 1951 with O.S.C.A. HWM made their debut with drivers George Abecassis and Stirling Moss. They would only enter the season opener, before returning in .

Mid-season changes

Future champions BRM made their debut in the British Grand Prix with Peter Walker and Reg Parnell. It would be their only start, before returning in . Luigi Fagioli made his return with Alfa Romeo in the French Grand Prix, in which the team manager ordered him to hand over his car to teammate Juan Manuel Fangio. Fagioli was allegedly so disappointed that he chose to retire from the sport immediately. Felice Bonetto replaced him as Alfa Romeo's third driver, while Consalvo Sanesi left the team.

Calendar Round Grand Prix Circuit Date 1 Swiss Grand Prix Circuit Bremgarten, Bern 27 May 2 Indianapolis 500 Indianapolis Motor Speedway, Speedway 30 May 3 Belgian Grand Prix Circuit de Spa-Francorchamps, Stavelot 17 June 4 French Grand Prix Reims-Gueux, Gueux 1 July 5 British Grand Prix Silverstone Circuit, Silverstone 14 July 6 German Grand Prix Nürburgring, Nürburg 29 July 7 Italian Grand Prix Autodromo Nazionale di Monza, Monza 16 September 8 Spanish Grand Prix Pedralbes Circuit, Barcelona 28 October

Calendar changes The Monaco Grand Prix was dropped from the calendar due to budgetary concerns and a lack of regulations in the sport. The Swiss Grand Prix was moved from June to May to become the season opener. The British Grand Prix was moved back from May to July. For the first time, the German and Spanish Grand Prix featured on the calendar as championship rounds.

World Championship season summary

Ferrari's newer, naturally aspirated 4.5-litre cars offered a real challenge to the Alfas, which were nearing the end of their development potential. The Ferraris were able to capitalize on the inefficiency of the Alfa's very thirsty engines, particularly at Silverstone. Although Alfas won four races, with Fangio taking the championship, Ferrari's three victories spelled the end for the Alfas. BRM made their only championship appearance with the V16 at Silverstone, and the old, slow Talbots were increasingly outclassed.

Points were given to the top 5 finishers (8, 6, 4, 3, 2). One point was given for the fastest lap. Only the best four of eight scores counted towards the world championship. Points for shared drives were divided equally between the drivers, regardless of who had driven more laps.

Pre-season non-championship races Although the official championship season would start in late May in Switzerland, a handful of non-championship events were to be run. The first was the first-ever Syracuse Grand Prix near the ancient city of Syracuse on the southern island of Sicily. This race was won by Italian Luigi Villoresi driving the new 4 1/2 litre Ferrari 375 on the public road circuit. Villoresi would triumph again two weeks later at Pau in southwest France over homeland hero Louis Rosier and Nino Farina, driving a Maserati for this race. On the same day, Thai driver Birabongse Bhanudej would triumph at the Richmond Trophy race at Goodwood in southern England in his Maserati.

Three weeks after the Goodwood and Pau races, it was the San Remo Grand Prix in western Italy, not far from Monaco. Alberto Ascari made his first appearance of the season and promptly won in a Ferrari 375 on this twisty and demanding street circuit, ahead of his countryman Dorino Serafini and Swiss Rudi Fischer, both in Ferraris. A week later was the Bordeaux Grand Prix in western France, and it was won by Rosier in a Talbot, ahead of Fischer and Briton Peter Whitehead in a Ferrari. Besides Farina, this race did not feature any Italians because they were competing in the Mille Miglia.

A week later was the BRDC International Trophy race at Silverstone, with the Alfa Romeos making their first appearance in 1951. Of the first two heats, Fangio won the first while Farina won the second, and Reg Parnell won the final all-important event, which was stopped because of torrential rain and flooding. Two weeks after this was the Paris Grand Prix in the Bois de Boulogne Park in the French capital city, which Farina won in a Maserati.

Round 1: Switzerland

A week after the BRDC International Trophy race, the Formula One Championship season started in Switzerland at the very dangerous and tree-lined Bremgarten public road circuit near Bern around the time the Monaco Grand Prix would have been held, but that historic race was not held this year. Alfa Romeo, the dominant team in 1950 with its supercharged 159 Alfetta, took the first five places on the grid, except 3rd, which Luigi Villoresi took in a Ferrari. Argentine Juan Manuel Fangio was on pole position, with his Italian teammate Giuseppe "Nino" Farina alongside him. The race started while it was raining, and with its overhanging trees lining the road, this circuit was even more dangerous in the wet. But Fangio made no mistake and won the race from Piero Taruffi in a Ferrari and Farina, whose decision to run the race without changing tires proved wrong.

Round 2: Indianapolis 500

The Indianapolis 500 in the United States was run three days after the Swiss Grand Prix on a Wednesday. It was the only non-European championship round and the only round that was not run to FIA Grand Prix regulations. Lee Wallard won this demanding race in his Kurtis Kraft-Offenhauser.

Round 3: Belgium

Farina won the Ulster Trophy at the Dundrod circuit in Northern Ireland in an Alfa Romeo. The following championship Grand Prix took place at the 14-kilometer (8.7 mi) Spa-Francorchamps circuit in Belgium. Fangio and Farina held the first two positions, while the Ferraris of Villoresi and Alberto Ascari held third and fourth. The race had 13 entries. Farina won the race, finishing ahead of Ascari and Villoresi. Fangio finished in ninth place, four laps behind, due to a mechanical issue with a wheel hub.

Round 4: France

The French Grand Prix, given the honorary designation of the European Grand Prix this year, was held at the Reims-Gueux circuit. Fangio, on pole again, was beaten off the line by 3rd-placed qualifier Ascari, with 2nd-placed qualifier Farina having a poor start and dropping to 11th. About 10 laps into the race, Ascari retired his car with a broken gearbox, and Fangio’s engine developed a misfire. Farina made up for the slow start and eventually took the lead. Argentine José Froilán González was 2nd in a Ferrari, and Italian Luigi Fagioli in an Alfa was 3rd in a one-off appearance this year. Farina's car developed magneto problems and he had to fall back, which put González in the lead, with Fagioli in 2nd. However, during their pitstops, González handed his car over to Ascari, and Fagioli had to exchange his healthy car with Fangio's mechanically unhealthy car (Drivers switching cars was commonplace in Formula One in the 1950s). This meant that Ascari and Fangio were back in 1st and 2nd where they had been before. But Fangio took advantage of Ascari's brake problems on his Ferrari to win a race that holds the record for the longest racing distance ever completed for a Grand Prix at . Fagioli, finishing 22 laps down and furious over having to swap cars with Fangio, quit Grand Prix racing afterwards.

Round 5: Britain